A4491: Triple Output Step-Down Switching Regulator

Designed to provide the power supply requirements of printers, office automation, industrial, and portable equipment, the A4491 provides three high current, high performance, switching regulator outputs in a single package, saving space, cost and component count.

High frequency switching allows selection of inexpensive inductors and small ceramic output capacitors. The turn-on cycles of the regulators are interleaved to minimize stresses on the input capacitors and to reduce EMI. Independent Enable pins simplify power sequencing and shutdown capabilities, and a power-on-reset (POR) circuit with user configurable delay indicates when enabled regulators are in specification. The POR flag also indicates when the input voltage drops below specification, giving the system controller advance warning while the switchers continue to operate down to the shutdown level.

Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm.